A man is standing on the edge of a 20.0 m high cliff. He throws a rock horizontally with an initial velocity of 10.0 m/s. How long does it take to reach the ground? How far does the rock land from the base of the cliff?

d = 20.2 m

t = 2.02 s

Explanation:

Horizontal Motion

When an object is thrown horizontally with a speed v from a height h, it describes a curved path ruled by gravity until it hits the ground.

To calculate the time the object takes to hit the ground, we use the equation:

Note the time does not depend on the initial speed.

The range or maximum horizontal distance traveled by the object can be calculated as follows:

The man standing on the edge of the h=20 m cliff throws a rock with a horizontal speed of v=10 m/s.

The time taken by the rock to reach the ground is:

t = 2.02 s

Now for the horizontal range:

d = 20.2 m

gpe = mass x gravity constant x height or… gpe = mgh

where… mass: measured in kilograms (kg)

gravity: gravity constant on earth = 10.00 m/s2

height: measured in meters (m)

gpe: measured in joules (j) or kilojoules (kj)

how do you solve gpe?

gravitational potential energy (gpe) is the energy an object has because of its position above the. ground.

gpe = mass x gravity constant x height or… gpe = mgh.

mass:

note: to earn full marks when solving science word problems, you must show your work:

formula.

example:

given values:

mass = 0.3 kg.